The purpose of this study is to obtain pilot data on the safety and feasibility of continuous cerebrospinal fluid (CSF) sampling via an indwelling lumbar catheter for a period of 30 hours. We have completed the study of five (5) normal healthy adult subjects. All five had intact neurological exams prior to admission, at the time the lumbar catheter was removed, and at the time of discharge from the hospital. None of the subjects showed any clinically significant changes in vital signs during the testing nor any signs of infection. In general, our experience with the procedure was nearly identical to that reported by other investigators performing the technique at the various sites around the country. We are now preparing to assay various neurochemicals in the CSF we have obtained.